High-Curie-temperature ferromagnetism in self-organized Ge1−xMnx nanocolumns
| Autor: | Pascale Bayle-Guillemaud, Romain Dujardin, Joel Cibert, Alain Marty, J. Rothman, Serge Tatarenko, Edith Bellet-Amalric, A. Barski, Matthieu Jamet, Richard Mattana, Thibaut Devillers, V. Poydenot |
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| Rok vydání: | 2006 |
| Předmět: |
Materials science
Condensed matter physics Magnetoresistance Silicon Spintronics Mechanical Engineering chemistry.chemical_element General Chemistry Condensed Matter Physics Epitaxy Ferromagnetism chemistry Mechanics of Materials Hall effect Curie temperature General Materials Science Saturation (magnetic) |
| Zdroj: | Nature Materials. 5:653-659 |
| ISSN: | 1476-4660 1476-1122 |
| DOI: | 10.1038/nmat1686 |
| Popis: | The emerging field of spintronics would be dramatically boosted if room-temperature ferromagnetism could be added to semiconductor nanostructures that are compatible with silicon technology. Here, we report a high-TC (>400 K) ferromagnetic phase of (Ge,Mn) epitaxial layer. The manganese content is 6%, and careful structural and chemical analyses show that the Mn distribution is strongly inhomogeneous: we observe eutectoid growth of well-defined Mn-rich nanocolumns surrounded by a Mn-poor matrix. The average diameter of these nanocolumns is 3 nm and their spacing is 10nm. Their composition is close to Ge2Mn, which corresponds to an unknown germanium-rich phase, and they have a uniaxially elongated diamond structure. Their Curie temperature is higher than 400 K. Magnetotransport reveals a pronounced anomalous Hall effect up to room temperature. A giant positive magnetoresistance is measured from 7,000% at 30K to 200% at 300K and 9 T, with no evidence of saturation. |
| Databáze: | OpenAIRE |
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